Droplets impact on textured surfaces: Mesoscopic simulation of spreading dynamics

Yuxiang Wang, Shuo Chen

Research output: Contribution to journalArticleResearchpeer-review

70 Citations (Scopus)

Abstract

Superhydrophobic surfaces have attracted much attention due to their excellent water-repellent property. In the present study, droplets in the ideal Cassie state were focused on, and a particle-based numerical method, many-body dissipative particle dynamics, was employed to explore the mechanism of droplets impact on textured surfaces. A solid-fluid interaction with three linear weight functions was used to generate different wettability and a simple but efficient method was introduced to compute the contact angle. The simulated results show that the static contact angle is in good agreement with the Cassie-Baxter formula for smaller Ø S and F a , but more deviation will be produced for larger Ø S and F a , and it is related to the fact that the Cassie-Baxter theory does not consider the contact angle hysteresis effect in their formula. Furthermore, high impact velocity can induce large contact angle hysteresis on textured surfaces with larger Ø S and F a . The typical time-based evolutions of the spreading diameter were simulated, and they were analyzed from an energy transformation viewpoint. These results also show that the dynamical properties of droplet, such as rebounding or pinning, contact time and maximum spreading diameters, largely depend on the comprehensive effects of the material wettability, fraction of the pillars and impact velocities of the droplets.

Original languageEnglish
Pages (from-to)159-167
Number of pages9
JournalApplied Surface Science
Volume327
DOIs
Publication statusPublished - 1 Feb 2015
Externally publishedYes

Keywords

  • Contact angle hysteresis
  • Droplet impact
  • Energy dissipation
  • Many-body dissipative particle dynamics
  • Surface roughness

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